Many Americans went into personal debt before the economic recession hit the country in 2008. Why? For some men, the biggest factor may have been intense competition to find a spouse.

That's the suggestion of a new study co-authored by an MIT professor that analyzes the ways social settings can affect people's propensity to save or spend money. Geographic areas with unusually high ratios of men to women, as the study notes, are correlated with high levels of personal debt; in follow-up lab experiments, the researchers found that men are more willing to spend money quickly in social settings with marked gender imbalances.

"There is reason to believe that men are making financial decisions in a way that reflects the influence of the ratios of men and women," says Joshua Ackerman, an assistant professor of marketing at the MIT Sloan School of Management and one of the researchers who performed the study. "Seeing more men around them in these environments activates a competitive mindset, which leads to a short-term, spend-now approach."

And

Consider the case of Macon and Columbus, two Georgia cities located within 100 miles of each other. In Columbus, there are 1.18 single men for every single woman, while in Macon, there are 0.78 single men for every single woman. As it happens, the average consumer debt in Columbus is $3,479 higher, per capita, than it is in Macon.

And:

When shown images with many more men than women, men in the study were willing to reduce their savings by 42 percent, and were willing to assume 84 percent more debt. "When men see more men than women in these photograph arrays, they become more likely to want to spend money more quickly, even to the point of going into debt," Ackerman observes.